It is possible for a single word to have more than one sense. For example, the word hand can refer to the body part at the end of our arms; the pointer on the dial of a clock; a bunch of bananas; the group of cards held by a single player in a card game; or a hired worker. Words that have two or more senses are said to be ambiguous (more precisely, polysemous; see Chapter 5).
A deictic expression such as my father will refer to different individuals when spoken by different speakers, but this does not make it ambiguous. As emphasized above, the fact that a word or phrase can have different denotations in different contexts does not mean that it has multiple senses, and it is important to distinguish these two cases. We will discuss the basis for making this distinction in Chapter 5.
If a phrase or sentence contains an ambiguous word, the phrase or sentence will normally be ambiguous as well, as illustrated in (13).
(13) Lexical Ambiguity
a. A boiled egg is hard to beat.
b. The farmer allows walkers to cross the field for free, but the bull charges.
c. I just turned 51, but I have a nice new organ which I enjoy tremendously.7
An ambiguous sentence is one that has more than one sense, or “reading”. A sentence which has only a single sense may have different truth values in different contexts, but will always have one consistent truth value in any specific context. With an ambiguous sentence, however, there must be at least one conceivable context in which the two senses would have different truth values. For example, one reading of (13b) would be true at the same time that the other reading is false if there is a bull in the field which is aggressive but not financially sophisticated.
In addition to lexical ambiguity of the kind illustrated in (13), there are various other ways in which a sentence can be ambiguous. One of these is referred to as structural ambiguity, illustrated in (14a–d). In such cases, the two senses (or readings) arise because the grammar of the language can assign two different structures to the same string of words, even though none of those words is itself ambiguous. The two different structures for (14d) are shown by the bracketing in (14e), which corresponds to the expected reading, and (14f) which corresponds to the Groucho Marx reading. Of course, some sentences involve both structural and lexical ambiguity, as is the case in (14c).
(14) Structural Ambiguity8
a. Two cars were reported stolen by the Groveton police yesterday.
b. The license fee for altered dogs with a certificate will be $3 and for pets owned by senior citizens who have not been altered the fee will be $1.50.
c. For sale: mixing bowl set designed to please a cook with round bottom for efficient beating.
d. One morning I shot an elephant in my pajamas. How he got into my pajamas I’ll never know.9
e. One morning I [shot an elephant] [in my pajamas].
f. One morning I shot [an elephant in my pajamas].
Structural ambiguity shows us something important about meaning, namely that meanings are not assigned to strings of phonological material but to syntactic objects.10 In other words, syntactic structure makes a crucial contribution to the meaning of an expression. The two readings for (14d) involve the same string of words but not the same syntactic object.
A third type of ambiguity which we will mention here is referential ambiguity. (We will discuss additional types of ambiguity in later chapters.) It is fairly common to hear people using pronouns in a way that permits more than one possible antecedent, e.g. Adams wrote frequently to Jefferson while he was in Paris. The pronoun he in this sentence has ambiguous reference; it could refer either to John Adams or to Thomas Jefferson. It is also possible for other types of NP to have ambiguous reference. For example, if I am teaching a class of 14 students, and I say to the Dean My student has won a Rhodes scholarship, there are multiple possible referents for the subject NP.
A famous example of referential ambiguity occurs in a prophecy from the oracle at Delphi, in ancient Greece. The Lydian king Croesus asked the oracle whether he should fight against the Persians. The oracle’s reply was that if Croesus made war on the Persians, he would destroy a mighty empire. Croesus took this to be a positive answer and attacked the Persians, who were led by Cyrus the Great. The Lydians were defeated and Croesus was captured; the empire which Croesus destroyed turned out to be his own.
7 From e-mail newsletter, 2011.
8 These examples are taken from Pinker (1994: 102). The first three are said to be actual newspaper examples.
9 Groucho Marx, in the movie Animal Crackers.
10 Kennedy (2011: 514).
